Rheostat



I. T. DANIELS.

, RHI-:05ML

APPLICATION FILED AUG-5. 1920.

/ INS ULATING MTERIAL.

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i i i g E Patented Jani 4, 1921.

UNITED s'rxrlfzs PATENT OFFICE.

JOHN T. DANIELS, OF NEIVABK, NEW' JERSEY7 .ASSIGNOR TO THE HANSON & VAN WINKLE C0., OF NEWARK, NEW JERSEY, A CORPORATION OF NEW JERSEY.

RHEOSTAT.

Application filed August 5, 1920.

T 0 all whom t may concern:

Be it known that I, JOHN T. DaNrnLs, a citizen of the United States, and residing in Newark, county of Essex, State of New Jersey, have invented certain new and useful Improvements in Bheostats, of which the following is a clear description, the par ticular novel features being more fully pointed out in the annexedv claims.

My improvements relate particularly to rheostats for low voltage but heavy current work, such as is required in electroplating or kindred arts, where fine regulation of strong currents by means of rheostats is essential.

In the ordinary commercial rheostats, the resistance units are usually arranged so, that they are gradually connected in series by the control lever, but they cannot at will also be thrown in parallel to each other or in mul'- tiple series, by which latter connections the resistance between the two main terminals of the rheostat may be varied to a very fine degree. By my improved arrangement and manner of connection of the resistance units, the above purpose may be attained in a very simple and convenient manner.

My invention is illustrated in the accompanying drawings, in which- Figure l is a plan view of the rheostat. showing the protecting casing partly broken away;

Fig. 2 is a transverse vertical section on the line 2-2, in Fig. 1 seen in the direction of the arrows, and

Fig. 3 is a wiring diagram showing several combinations of the units in multiple series.

Referring to Figs. 1 and 2, 30 is a base plate of appropriate insulating material near the opposite longitudinal edges of which plate are mounted, in parallel to each other, two terminal rails 3l and 83 provided respectively with the binding posts 32, Sil, by which the rheostat is connected into the working circuit. Adjacent to each rail is mounted an equal numbered row of terminal blocks 35, the blocks being insulated from their respective rails and from each other by the base plate. Between these two rows of blocks the resistance elements 36 are connected in zig-zag fashion, as is shown in Figs. l and 3, so that each block forms the common terminal for the ends of two adjacent resistance units, the opposite ends of Specification of Letters Patent.

Patented Jan. 4C, 1921.

Serial No. 401,287.

which are connected to two adjacent blocks f the opposite row.

To each terminal block 85 isconductively fastened one end of a. contact leaf spring 37, the opposite ends of the springs extending over the adjacent terminal rail. rIhis is clearly shown in Figs. l and 2.

Each spring 37 is slotted midway between its ends and each spring has disposed in its slot a lifting finger 38 of insulating material, this `linger being held in place by means of a pivot ain 59 which seats in a semi-circularl'y curved portion of the spring, so that the inner end of the linger is forced by the spring tension against the terminal rail over which the spring is located. Each spring is shaped so that when its finger is thrown by the operatcr toward the center of the rheostat, the free spring end is lifted off its respective terminal rail, and when its finger is thrown outwardly the free end is permitted to seat on the rail and to establish an electric contact straight lines, numbered from 1 to 19, and

only those switches, which are assumed to be closed, are indicated by a dotted arc.

If now, for instance. the upper end of unit l is connected to its terminal rail 3l and the lower end of unit 3 is connected to its rail 83, then units l, 2, 3 are connected in series between rails 31 and 33.

Likewise if the upper end of unit 6 is connected with rail 3l in addition, units Il, 5 and 6 are connected in series between the two rails and form a group in parallel to the above described unit group l., 2, 3. Further smaller or larger series groups may be added in multiple, for example, by closing the switches at the upper ends of units l2 and 14 and at the lower ends of units 1l, I3 and 15; or also only the switch at the upper end of unit l and at the lower end of unit 19 may be closed.,l when all units are thrown in series. In other words. this arrangement aftords the possibility for the opcrater to quickly and conveniently produce many series and multiple series connections et the units, and thus to vary the resistance oft the rheostat within Very line steps, which in the ordinary control lever operated rheostats would require a large number ot units and a number of ini-,iif'idnal rheostats.

The resistance units are protected from mechanical injury by a casing l() (shown in l and 9') against which the banks ot switch Fingers may conveniently rest, when the switches are open, and thus the condition ot each bank may be observed by the operator at a glance. Ventilation openings tl may be provided in the top and sides oi' this casing` te permit air cooling` of' the resi stance units.

l claim l. A rheostat et the character described, comprising two terminal. rails mounted in parallel to and a distance apart :troni each other, two rows ot terminal blocks mounted between the rails, one row adjacent to each rail a plurality ot resistance units connecting;` the blocks et said opposite rows in zig- Zag;v fashion, and a bank ot switches for each row, adapted to individually connect each block with its adjacent rail at will.

2. A rheostat of the character described, comprising' two terminal rails mounted in parallel to and a distance apart from each other, two rows of terminal blocks mounted between the rails, one row adjacent to each rail, a plurality ot' resistance units connectinn,- the blocks of said opposite rows in Zig- Zag fashion, and a bank ot' switches for each row contaiuning` one switch tor each block.

each switch consisting of a lealI snrinp,` tas tened at its inner end to its block and having its outer end extending over the adjacent rail, a lifting linger pivotally attached to each spring` intermediate the linger ends and resting` with its inner end against the rail to permit7 when moved on its pivot in one direction, the seating' ot the tree springend on the rail` and, when moved in the other direction, lifting the said'spring end from the rail.

A rheostat of the character described, coinjirising` two terminal rails mounted in parallel to and a distance apart from each other, two rows ot terminal blocks mounted between the rails. one row adjacent to cach rail, a plurality of resistance units connecting` the blocks of said opposite rows in zig'- tashion, and a bank of switches for each row, containingone switch for each block, each switch consisting ot a leaf spring fastened at its inner end to its block and havingJ its outer end extendingover the adjacent rail, a lifting linger pivotally attached to each spring intermediate the linger ends and resting,` with its inner end against the rail to permit, when moved on its pivot. in one direction, the seatingol the free spring end on the rail7 and, when moved in the other direction, lifting the said spring end from the rail, and a protecting casing, covering` said resistance units, and serving as an abutment 'for the free ends ot' all ot said switch lingers when their respective Contact springs are lifted from the rails.

JOHN T. DANIELE). 

